architect

Imported from JeongJaeSoon/agent-skills (skills/architect/SKILL.md). Install upstream with npx skills add JeongJaeSoon/agent-skills --skill architect. Copyright stays with the author.

Architect

Design before implementing. Sketch types, function signatures, class shapes, and module boundaries with not implemented bodies and pseudocode. Synthesize across multiple model perspectives, then fill in code against the chosen sketch. If implementation proves the sketch wrong, throw it out and redesign.

Start

Open a todolist with one entry per phase before starting.

1. Ground
2. Sketch
3. Agree
4. Implement
5. Scrap

A principle skill below is references/principle-<name>.md in the principles skill.

Phase A: Ground the problem

Build a real mental model of every system the new code touches. Run the how skill over the relevant subsystems.

Naming a file isn't grounding. Produce the traced model how prescribes. If the design redefines ownership or layering, also recover why the existing shape is the way it is (git log -S / git blame on the load-bearing lines, and the PRs and tickets they cite) so the rationale becomes a constraint, not a guess. pstack's why skill, which upstream uses here, is not installed.

Skip Phase A only when the work is genuinely greenfield with no surrounding system to integrate.

Phase B: Sketch

Fan out one runner per row below, launched in the same message, with the design-sketch task and the Phase A grounding artifacts. Pass references/runner-prompt.md as each runner's prompt, with the absolute paths of this SKILL.md and references/rationale-template.md so a runner can read them, and a separate output path per runner so candidates stay independent. Each candidate produces a design package shaped per references/rationale-template.md.

Run one Codex job at a time; two concurrent jobs kill each other. If a model name is rejected, use the closest available tier of the same family and say which one ran.

Design it twice. Require at least two structurally distinct candidates before synthesis, even when the first looks sufficient. This is the exhaust-the-design-space principle skill made concrete. Whole-shape alternatives, not point fixes inside one shape.

Screen every candidate against references/design-red-flags.md before synthesis. Reject or revise shallow modules, information leakage, temporal decomposition, and pass-through methods.

Compare viable candidates on interface depth. Prefer the design that hides more complexity behind a smaller, simpler public surface. A rich interface can keep call chains short by concentrating capability instead of scattering it across layers.

You synthesize the viable candidates into one design package: pick the base, graft what each other candidate did better, and record the choice in the rationale's "Synthesis decision" section. (Upstream hands this step to pstack's arena skill, which is not installed here.)

Phase C: Agree (opt-in)

Default: proceed directly to implementation with the synthesized design. No human checkpoint.

Opt in to a checkpoint when the invoker explicitly asks: "/architect with checkpoint," "stop and show me before implementing," or similar. Then surface the synthesized design and pause for sign-off.

The synthesis can ship as its own commit either way, as the "scaffold first" mode of the foundational-thinking principle skill. Planned and scoped breakage during fill-in is fine, per the outcome-oriented-execution principle skill. For adversarial pressure on the design before implementing, run the interrogate skill on the synthesized sketch.

If the human pushes back on the shape (in a checkpoint or after the fact), treat that as Phase A evidence. Re-ground and re-run Phase B before writing more code.

Phase D: Implement against the sketch

Replace not implemented bodies with code, pseudocode with logic. The synthesized sketch is the contract.

Deviations from the sketch are signal worth surfacing, not friction to absorb silently. If a function needs a parameter the sketch didn't anticipate, ask whether the sketch was wrong, the requirement was missed, or the implementation is overreaching.

Phase E: Scrap when the architecture is wrong

If implementation keeps producing friction the sketch can't absorb, throw the sketch out. Don't bolt fixes onto a wrong design, per the redesign-from-first-principles and fix-root-causes principle skills.

The signal is a pattern, not single instances. Tells:

• The same shape of workaround appearing repeatedly across unrelated code.
• Multiple unrelated edge cases that all need special-case branches.
• Types that need escape hatches (any, casts, optional fields always set in practice) to compile.
• The "we need a lock" reflex when the sketch said the state wasn't shared.
• Callers having to know the abstraction's internal rules to use it.
• Two or more independent Phase D deviations of the same shape across the implementation.

Use judgment. A few edge cases don't condemn an architecture. Some problems are legitimately complex. Complexity in the data is not complexity in the design.

When you scrap:

1. Re-run the how skill over what's been built.
2. Redesign as if the new constraints had been day-one assumptions, per redesign-from-first-principles.
3. Subtract before adding, per the subtract-before-you-add principle skill. The new sketch should be smaller than the old one before it grows.
4. Return to Phase B and re-run the fan-out.

Outputs

The caller's usage is written first and the type sketch derived from it. One file with new types and signatures for small changes. Module map plus type definitions for larger work. The rationale ships alongside, shaped per references/rationale-template.md, including the usage sketch and the synthesis decision.